Working in the Galapagos archipelago, scientists have captured an elusive moment in the history of a group of birds – the creation of a new species from a new strain. Daphne Major's native medium ground finch (left), and the new species (right)

Peter and Rosemary Grant/Proceedings of the National Academy of Sciences

A herd of African elephants walks in Addo elephant national park, South Africa. Illicit trade in ivory is on the increase, according to an analysis of seizure data in the Elephant Trade Information System (ETIS)

A painted lady butterfly. Scientists believe they have solved the long-standing mystery of where painted lady butterflies go in winter – with the help of Butterfly Conservation's monitoring scheme, in which members of the public registered sightings online. It has produced 12,000 reports of the butterflies from the UK and across Europe since the beginning of the year. The insects were seen around the Channel coasts of Cornwall, Devon, Sussex and Kent and arriving back in the Mediterranean and north Africa

A Siamese crocodile at Phnom Tamao wildlife rescue centre in Phnom Tamao village, Cambodia. Conservationists searching for one of the world's most endangered crocodiles have found dozens at the centre. After studying DNA from 69 crocodiles at the centre, scientists found nearly 50% were Siamese crocodiles, which until recently were believed to have gone extinct in the wild

Colonies of army ants are usually antagonistic to each other, attacking soldiers from rival colonies in border disputes that keep the colonies separate. But new work by a researcher at the Harvard Museum of Comparative Zoology and the University of Copenhagen shows that in some cases the colonies can be cooperative instead of combative

A coot flies across the water after being released at Eastshore state park in Berkeley, California. Fifteen rehabilitated birds that were rescued from San Francisco Bay after an oil spill from the Dubai Star vessel on October 30 were released back into the wild. Thirty-six birds died from the oil spill

A howler monkey that was rescued from a life as a pet, snacks on fruit at Ambue Ari jungle reserve in Bolivia. The monkey regularly drank alcohol and watched TV all day and his troubled past makes it unlikely that he can be released into the wild

A group of twig catfish (Farlowella vittata) hatchlings. One of Smithsonian national zoo's best-camouflaged creatures comes out of its hiding place to spawn. Twig catfish are native to the Amazon, Orinoco and Paran rivers of South America and typically camouflage themselves within dead leaves and stick debris